1. Field of the Invention
The present invention relates to a color photographic light-sensitive material providing color images with improved fastness and improved sharpness and capable of being rapidly processed at an elevated temperature and, more particularly, to a color photographic light-sensitive material in which fogging caused by development at an elevated temperature, for example, above about 30.degree. C, can be controlled and which has improved stability.
2. Description of the Prior Art
In recent years, it has eagerly been desired to provide a color light-sensitive material capable of being developed rapidly, for example, in a short time of less than 6 minutes, particularly less than 3 minutes. For this purpose, various techniques have been tried. For example, silver halide grains exhibiting a rapid color development rate, i.e., silver bromoiodide or silver bromochloride grains or silver halide grains obtained by conversion have been used, couplers permitting rapid color development alone or in combination have been used, or an accelerator for color development or a sensitizer, e.g., onium salts, polyoxyethylene residue-containing compounds, 3-pyrazolidone derivatives, imidazole compounds, and compounds capable of releasing a development accelerator upon development have been used.
On the other hand, various techniques have also been tried in the development processing step. For example, development processing at an elevated temperature, particularly about 30.degree. C. or above, or use of a color developing agent exhibiting a rapid developing rate, use of a development accelerator, employing blix processing, applying a process for obtaining color images through a combined developing processing, or the like have been attempted.
Furthermore, another technique is to use couplers allowing a reduction in the content of silver halide necessary for forming color images, e.g., 2-equivalent couplers. Couplers in accordance with this purpose are not necessarily 2-equivalent couplers, and 4-equivalent 3-anilino-5-pyrazolone couplers exhibiting good coloring efficiency are also usable. Also, the so-called colored couplers wherein one hydrogen atom of the active methylene group is replaced by an azo group are also useful as magenta couplers. Of the 2-equivalent couplers, those wherein a nitrogen atom of the coupling off group is connected to a carbon atom of the active methylene group are particularly useful for this purpose.
When color light-sensitive materials to which the above-described various techniques have been applied are subjected to rapid processing, fog tends to be formed. In particular, when these materials are rapidly developed at an elevated temperature, fogging tends to occur. Various techniques can be used for controlling fogging in color development. For example, phenol derivatives, in particular, hydroquinone derivatives, mercapto compounds such as 1-phenyl-5-mercaptotetrazole, 5-nitrobenzotriazole, 2-mercaptobenzimidazole, etc., and other heterocyclic compounds capable of forming silver salts can be used. These compounds, however, produce in turn new disadvantages in that they desensitize the silver halide emulsion, deteriorate the gradation (gamma), or gradually reduce the sensitivity with the lapse of time.